There's only a couple of controls, you think. How hard can it be, you question. The answer is, very hard indeed, so forget about the apparent simplicity of Wind-up Knight, because it's all superficial - this is the hardest game of all time.

Okay, it isn't, but it's a lot more tricky than you'd think at first glance. The idea is very simple: you are a knight powered by the kinetic energy stored in a wind-up mechanism. You must run - there's no way to stop the knight running, he's a veritable Forrest Gump - across a level collecting coins, defeating things that stand in your way, and you must do it with just a couple of controls.

Wind-up Knight (Android)

In many ways, it's just like Super Mario Bros. Character runs across the screen, and it's your job to keep him out of trouble. Annoyingly though, the wind-up knight isn't controllable to the extent Mario is, so you need to have your wits about you, if you're going to get from the start of a level to the end without impaling yourself on a spike, or getting p0wned by some sort of chicken.

In fact, the simplicity of the controls is a good thing, because on a touchscreen, anything more than simple and you won't be able to see your phone's screen for all the fingers in the way. Here, the interface is simple, there's one button for jump and one button for attack. The problem, of course, is that your brain gets confused and tells you to press one button when you should be pushing the other.

Graphically, it's lovely to look at. We ran our copy on a Note II, which has a quad core processor, so you might want to make sure you have a decent-sized screen, and enough power to play it. If you have an Xperia Play, you'll also be able to use the controller to play this game, which is a nice touch.

Now, a word about money. The game is free, but like other Robot Invader apps, it's actually "freemium". What the means is, there's a certain amount of fun to be had for free, but, at some point - if you're not extremely good - you need to pay to unlock other levels. And like most freemium games, there's stuff to make the game easier which you can buy along the way. Some of these you can get from points earned, or by "liking" the game on Google+ or Facebook.

Even so, you could just cough up for the full game with the levels unlocked, but it's probably safer to see if you actually like the thing first, because it is a VERY annoying game, but we're pretty sure once you start playing it, you won't be able to put it down again.